Paraffin scraping tool



June 22, 1943. L. o. CRANFORD 2,322,419

PARAFFIN SCRAPING TOOL Filed Sept. 18, 1940 Enventor lb yaz L96 awn/fwdf Ui/g m, f wf (Ittqnieg Patented June 22, 1943 ATENT oer-ice Y Panama:sonarma 'roor.

Lloyd Lee Ottis Cranium-d, Baton Rouge, La. Application September 18,race, Serial No. 357,327

Claims.

The present invention relates to tools and more particularly to an oilwell tool for scraping or removing paraflln or other accumulations fromthe casing or tubing thereof.

In'many oil wells paraflln or other accumulations collect on the innerwalls of the well casing or tubing and seriously impairs and obstructsthe free flow of oil therethrough.

It is an object of the present invention to provide a novel scrapingtool for cleaning the walls of the well tubing in a rapid andeificient'manner.

A further object of the invention is to provide a device of thischaracter which will easily cut through and remove heavily cakedmaterial encrusted on the walls of the well tubing.

Another object of the invention is the provision of a tool of thischaracter which is ofv simple and inexpensive construction, eflicientand durable in use.

With the foregoing and other objects in view, the invention will be morefully described hereinafter, and will be more particularly pointed outin the claims appended hereto.

In the drawing wherein like symbols refer to like or corresponding partsthrough the several views.

Figure l is an elevation view of a well scraping tool embodying thisinvention.

Figure 2 is an enlarged transverse sectional view taken on line 2-2 ofFigure 1.

Figure 3 is a similar view taken on line 3-3 of Figure 1, the partsshown in elevation.

Figure 4 is a similar sectional view taken on the line 5-4 of Figure 1.

Figure 5 is an enlarged cross-sectional view taken-along the line 55 ofFigure l.- I

Referring more particularly to the drawing, the numeral lil designatesan elongated body or rod which is tapered from its upper end to itslower or leading end, as illustrated in Figure 1. The upper end of therod I0 is provided with a reduced and threaded extension Ii forremovable connection to a suitable drill stem, anchor bar or otheractuating member l2. A groove 53 is disposed in the upper end of the rodl0 below the coupling extension H to permit fishing of the tool from thewell when necessary.

A series of four identical knives H are dis posed longitudinally of therod It! at a point adjacent to but spaced from the lower or leading endof the rod. The knives M are equally spaced about the rod or shaft I0 inhorizontal alignment and are semi-elliptical in shape, being set intolongitudinal slots in the body of rod with their curvededges sharpenedand extending outwardly from the surface of the rod. Screws i5 securethe knives H in the rod slots, as seen in Figures 1 and 4. v

A set of four scraping blades I6 are secured to the rod iii inhorizontal positions, said blades being equally spaceda substantialdistance apart. The upper blade I6 is spaced a substantial distancebelow the top of the rod in while the lower blade It is spaced asubstantial distance above the group of knives It. A knife i1, identicalwith knives iii, lssecured .in a slot below each of the blades id insame manner as knives I4, but each knife ill is spaced about thecircumference of the rod from the next adjacent knife H, as illustratedin Figure 1. As the rod i0 is tapered from the top to the bottom, theknives l'l pro- Sect radially beyond the knives below. Each knife ii isdisposed in' longitudinal alignment with one of the knives l 4.

Each of the blades i6 is of arcuate shape, extending through an arc ofabout 240 and may be formed by bending a steel band to the requisitearcuate or circular form. A reinforcing bar in is welded or otherwiserigidly attached betweenthe open ends of the blade near the rear edgesthereof. This bar I8 is bolted as at I9 Within a transverse slot in thesurface of the rod ll, whereby the center of the bar is flush with thelongitudinal surface of .the rod. Thus the bar it not only reinforcesthe blade I6 but also permits the blade to be spaced an equal distanceat all points from the rod.

The blades is are beveled from the inside to the top and from the insideto the bottom to provide top and bottom sharpened cutting edges asillustrated in Figure 1.

This design and arrangement results in the paraflln being shaved fromthe walls of the tubing and as the same is shaved it passes readilybehind the blades and is, of course caught in the stream of flowing oiland carried away.

The blades I6 are also spaced about the rod at points 90 apart and thecenter of each blade is disposed in vertical alignment with the knife llimmediately below it. The blade I6 at the upper end of rod I0 isradially wider than the next blade having the same radius as the bore ofthe well tube, and the blades are progressively smaller approaching thelower end of rod It.

In operation the rod 10 is lowered withinthe well casing and the knivesll will slice or cut into the paraffin or otheraccumulationcaked on thewalls of the casing. The knives I! will enter the same cuts, slicingthem deeper, while;

foreign matter or accumulation has been completely removed from thecasing.

Whil the blades I6 will also shave or scrape the walls on the upwardmovement of the tool, the progressive cutting and scraping of the bladesand knives is relied on to principally to'easily and effectively removethe caked material from the casing walls. Without this progressiveaction of cutting and scraping deeper and deeper as the tool progressesin its downward stroke, the caked material which collects on the wallsof the casing ofiers too great of a resistance to be removed effectivelyby ordinary scraping methods.

Although the knives and blades illustrated are in groups of four spaced90 apart, they may be obviously of any desired number, preferablyequally spaced about the circumference of the rod [0.

An important feature of this invention is the action of longitudinallyslicing or cutting the caked material before each successive scraperblade is brought into play, and the progressive deepening of the slicingand scraping action.

It is obvious that various changes and modifications may be made in thedetails of construction and design of the above specifically describedembodiment of this invention without departing frim the spirit thereof,such changes and modifications being restricted only by the scope of thefollowing claims:'

' What is claimed is:

1. In a well scraper, an elongated body member, a series of slicingknives with longitudinally arranged cutting edges secured on said bodymember adjacent the leading end thereof, said knives extending radiallyfrom the body member in longitudinally spaced staggered relation aboutits circumference, and a series of transverse scraping blades secured tothe body member above th slicing knives, said scraping blades andslicing knives being spaced apart longitudinally of the body member inalternate arrangement thereon, said scraper blades being disposed instaggered overlapping relation to one another and having arcuatescraping edges, each scraping blade of the series extending radiallybeyond the scraping blades disposed between it'and the leading end ofthe body member.

2. In a well scraper, an elongated body member, a series of slicingknives with longitudinally arranged cutting edges secured on said body-member adjacent the leading end thereof, said knives extending radiallyfrom the body mem- 'ber inlongitudinally spaced staggered relation aboutits circumfernece, and a series of transverse scraping blades secured tothe body member above the slicing knives, said scraping blades andslicing knives being spaced apart longitudinally of the body member inalternate arrangement thereon, said scraping blades being disposed instaggered relation and having arcuate scraping edges, each scrapingblade of the series extending radially beyond the scraping bladesdisposed between it and the leading end of the body member, and a knifewith a longitudinally disposed radially extending slicing blade arrangedin spaced relation ahead of each scraping blade and in alignment withthe central portion of said blade.

3. In a well scraper, an elongated body member, a series of slicingknives with longitudinally arranged cutting edges secured on said bodymember adjacent the leading end thereof, said knives extending radiallyfrom the body member in longitudinally spaced staggered relation aboutits circumference, and a series of transverse scraping blades secured tothe body member above the slicing knives, said scraping blades andslicing knives being spaced'apart longitudinally of the body member inalternate arrangement thereon, said scraper blades being disposed instaggred relation and having arcuate scraping edges, each scraping bladeof the series extending radially beyond the scraping blades disposedbetween it and the leading end of the body member, and a knife with alongitudinally disposed, radially extending slicing blade arranged inspaced relation ahead of each scraping blade and in alignment with thecentral portion of said blade, each of said last named slcing knivesbeing disposed in longitudinal alignment with one of the slicing knivesat the leading end of the body member and extending radiallytherebeyond.

4. In a well scraper, a body member, a series of arcuate scrapingelements carried by the body l member, said scraping elements extendingaircumferentially-about a body member and being spaced apartlongitudinally of the body member and disposed in staggered relationcircumferentially of the body member, each of the scraping elementsofthe series projecting radially outwardly beyond the scraping elementsbetween it and the leading end of the body member, and

- a series of circumferentially staggered longitudinally spaced slicingknives secured to said body member, each knife in the series beingdisposed below and in longitudinal alignment with one of the staggeredscraping element and adapted to slice the material on the well casingahead of the scraping elements.

5. In a well scraper, an elongated body member, a series oflongitudinally spaced arcuate transverse scraper. blades secured to thebody member in circumferentially staggered relation around the memberand adapted to scrape material from the walls of a well casing and aslicing knife disposed longitudinally on said body mem-

